1) In molecules, the stronger the intermolecular force is the higher the boiling point. In this case the intermolecular formula is weak since nitrogen gas (N2) and oxygen gas (O2) are non-polar molecules meaning that the intermolecular force between them is dispersion force. This will result in a low boiling point since not a lot of energy is needed to break the bond. This explains the reason why nitrogen and oxygen can exist as gases under normal environmental conditions.
2) As mentioned earlier the stronger intermolecular forces, the higher the boiling point.Therefore the weaker the intermolecular forces, the lower the boiling point. H2O and H2S are similar molecules with the same molecular geometry and they are both polar. Although oxygen atom in water is much more electronegative than the sulfur atom in hydrogen sulfide,This will result in a much more polar bond. In other words, the H2O molecule has much stronger bonds than the H2S molecule. Since the bonds of H2O are stronger, the intermolecular force is also greater, so the boiling point of the molecule is high. And since the bonds of H2S are weak, the intermolecular force is also weak, resulting in the boiling point to be much lower.
3) Sublimation occurs when a molecule changes from its solid state to its gaseous state without going through the liquid state. When iodine sublimes to gas, its intermolecular forces weaken through the process. When it first starts the intermolecular forces are strong and as it reaches to its gas state and the iodine particles start to move away from each otherthe intermolecular forces diminish resulting with no intermolecular force.
2) As mentioned earlier the stronger intermolecular forces, the higher the boiling point.Therefore the weaker the intermolecular forces, the lower the boiling point. H2O and H2S are similar molecules with the same molecular geometry and they are both polar. Although oxygen atom in water is much more electronegative than the sulfur atom in hydrogen sulfide,This will result in a much more polar bond. In other words, the H2O molecule has much stronger bonds than the H2S molecule. Since the bonds of H2O are stronger, the intermolecular force is also greater, so the boiling point of the molecule is high. And since the bonds of H2S are weak, the intermolecular force is also weak, resulting in the boiling point to be much lower.
3) Sublimation occurs when a molecule changes from its solid state to its gaseous state without going through the liquid state. When iodine sublimes to gas, its intermolecular forces weaken through the process. When it first starts the intermolecular forces are strong and as it reaches to its gas state and the iodine particles start to move away from each otherthe intermolecular forces diminish resulting with no intermolecular force.